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Groups > linux.kernel > #1287014
| From | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH perf/core 17/22] perf: Fix __machine__addnew_vdso to put dso after add to dsos |
| Date | 2015-12-09 03:30 +0100 |
| Message-ID | <qDCFZ-295-31@gated-at.bofh.it> (permalink) |
| References | <qDCwi-25G-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Fix __machine__addnew_vdso to put dso after add to dsos because
the dso is already gotten by the dsos via __dsos__add().
This function is called finally from machine__findnew_vdso()
which locks machine->dsos.lock. And before unlock it, the
function gets the dso's refcnt. Thus we can ensure that the
dso is not removed from the machine while this operation,
and we don't need to get the dso except for the machine->dsos.
refcnt debugger shows:
-----
$ ./perf top --stdio -v (note: run by non-root user)
[...]
==== [3] ====
Unreclaimed dso@0x27a0a30
Refcount +1 => 1 at
./perf(dso__new+0x2bc) [0x4a778c]
./perf(machine__findnew_vdso+0x272) [0x4e8792]
./perf(map__new+0x2db) [0x4bfb4b]
./perf(machine__process_mmap2_event+0xf3) [0x4bda33]
./perf(perf_event__synthesize_mmap_events+0x364) [0x484e74]
./perf(perf_event__synthesize_threads+0x3ee) [0x48583e]
./perf(cmd_top+0xdc2) [0x43cfb2]
./perf() [0x47ba35]
./perf(main+0x617) [0x4225b7]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f2b01387af5]
./perf() [0x42272d]
Refcount +1 => 2 at
./perf(machine__findnew_vdso+0x289) [0x4e87a9]
./perf(map__new+0x2db) [0x4bfb4b]
./perf(machine__process_mmap2_event+0xf3) [0x4bda33]
./perf(perf_event__synthesize_mmap_events+0x364) [0x484e74]
./perf(perf_event__synthesize_threads+0x3ee) [0x48583e]
./perf(cmd_top+0xdc2) [0x43cfb2]
./perf() [0x47ba35]
./perf(main+0x617) [0x4225b7]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f2b01387af5]
./perf() [0x42272d]
Refcount +1 => 3 at
./perf(dso__get+0x32) [0x4a7b52]
./perf(machine__findnew_vdso+0xc1) [0x4e85e1]
./perf(map__new+0x2db) [0x4bfb4b]
./perf(machine__process_mmap2_event+0xf3) [0x4bda33]
./perf(perf_event__synthesize_mmap_events+0x364) [0x484e74]
./perf(perf_event__synthesize_threads+0x3ee) [0x48583e]
./perf(cmd_top+0xdc2) [0x43cfb2]
./perf() [0x47ba35]
./perf(main+0x617) [0x4225b7]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f2b01387af5]
./perf() [0x42272d]
[...]
-----
The log shows that the machine__findnew_vdso gets a dso
so many unnaturally. I've traced the code and found this
bug.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
---
tools/perf/util/vdso.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index 44d440d..fea0d18 100644
--- a/tools/perf/util/vdso.c
+++ b/tools/perf/util/vdso.c
@@ -130,6 +130,8 @@ static struct dso *__machine__addnew_vdso(struct machine *machine, const char *s
__dsos__add(&machine->dsos, dso);
dso__set_long_name(dso, long_name, false);
}
+ /* Put the dso here because it is already gotten by __dsos__add */
+ dso__put(dso);
return dso;
}
--
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[PATCH perf/core 00/22] perf refcnt debugger API and fixes Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
[PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
Re: [PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-09 15:20 +0100
RE: [PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-10 10:00 +0100
Re: [PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso 'Arnaldo Carvalho de Melo' <acme@kernel.org> - 2015-12-10 20:30 +0100
[PATCH perf/core 20/22] perf: Fix maps__fixup_overlappings to put used maps Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
Re: [PATCH perf/core 20/22] perf: Fix maps__fixup_overlappings to put used maps Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-09 16:20 +0100
[tip:perf/core] perf tools: Fix maps__fixup_overlappings to put used maps tip-bot for Masami Hiramatsu <tipbot@zytor.com> - 2015-12-10 09:20 +0100
[PATCH perf/core 04/22] perf refcnt: refcnt shows summary per object Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
[PATCH perf/core 22/22] perf: Fix write_numa_topology to put cpu_map instead of free Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
Re: [PATCH perf/core 22/22] perf: Fix write_numa_topology to put cpu_map instead of free Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-09 16:30 +0100
[tip:perf/core] perf tools: Fix write_numa_topology to put cpu_map instead of free tip-bot for Masami Hiramatsu <tipbot@zytor.com> - 2015-12-10 09:20 +0100
[PATCH perf/core 05/22] perf: make map to use refcnt Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
[PATCH perf/core 17/22] perf: Fix __machine__addnew_vdso to put dso after add to dsos Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> - 2015-12-09 03:30 +0100
Re: [PATCH perf/core 17/22] perf: Fix __machine__addnew_vdso to put dso after add to dsos Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-09 15:40 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-09 14:50 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2015-12-10 04:40 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes Namhyung Kim <namhyung@kernel.org> - 2015-12-10 06:00 +0100
RE: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-10 09:40 +0100
RE: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-10 12:10 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes "Wangnan (F)" <wangnan0@huawei.com> - 2015-12-10 14:00 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 'Arnaldo Carvalho de Melo' <acme@kernel.org> - 2015-12-10 16:20 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes "Wangnan (F)" <wangnan0@huawei.com> - 2015-12-11 03:00 +0100
RE: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-11 03:10 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes "Wangnan (F)" <wangnan0@huawei.com> - 2015-12-11 03:30 +0100
RE: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-11 03:20 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes "Wangnan (F)" <wangnan0@huawei.com> - 2015-12-11 03:50 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes "Wangnan (F)" <wangnan0@huawei.com> - 2015-12-11 04:00 +0100
RE: [PATCH perf/core 00/22] perf refcnt debugger API and fixes 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> - 2015-12-11 05:00 +0100
Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-11 23:30 +0100
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